The general principle of solar thermal technology is based on the concept of the concentration of solar radiation to produce generally steam, which is then used in standard power plants.
Solar energy collection, which has a relatively low density, is one of the greatest challenges in the development of solar thermal power plants. There are two types of solar concentrators: linear concentrators and point concentrators. Linear concentration is easier to install since it has fewer degrees of freedom, but it has a lower concentration factor and therefore it can reach lower temperatures than point concentration technology.
That is why an effort is made in order to progress in the development of the receiving tubes used in linear concentration, to try to increase the concentration factor achieved therein and to reduce losses, such that the overall performance of the concentration plant increases.
The invention before us explains the procedure of assembly of one of these receiving tubes of improved technology with respect to what exists in the state of the art, as well as the resulting tube.
In general, a receiving tube consists of two concentric tubes between which the vacuum is produced. The inner tube, through which the fluid that is heated flows, is made of metal and the outer tube is made of glass, usually borosilicate.
Between the metal tube and the glass tube, at the ends of the tube, there will be installed a series of elements or devices each with a specific function. The most common are: expansion compensating device or bellow, evaporable getter or vacuum detector, non-evaporable getter or vacuum-enhancing system and different connection elements necessary between these devices.
As for the background on this type of procedures none in particular are worth mention since, depending on the components of the specific tube that is going to be manufactured, the assembly procedure shall be conducted in one way or another. As an example of tube, but that has different design elements and located in different places and not being an object of this document to detail them, patent US 20070209658 by SCHOTT can be mentioned.